Hacker Rank: Pairs

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...

        int numberOfIntegers = 0;
        scanf("%d", &numberOfIntegers);

        int difference = 0;
        scanf("%d", &difference);

        NSMutableSet *set = [NSMutableSet setWithCapacity:10000];
        int total = 0;
        
        for (int i = 0; i < numberOfIntegers; i++) {
            
            long number = 0;
            scanf("%ld", &number);
            
            long remainder = 0;
            
            if (number > difference) {
                 remainder = number - difference;
                if ([set containsObject:[NSNumber numberWithLong:remainder]]){
                    total++;
                }
                
            }
            
            remainder =  difference + number;
            
            
            if ([set containsObject:[NSNumber numberWithLong:remainder]]){
                total++;
            }
            
            [set addObject:[NSNumber numberWithLong:number]];
  
        }
        
        printf("%d",total);
     }

    return 0;
}